MI5 has launched two urgent inquiries into how it missed the danger posed by the Manchester bomber, Salman Abedi, amid claims his interest in being a potential terrorist killer was repeatedly reported to the authorities.

Britain’s domestic security service started one review last week, which will aim to quickly identify any glaring errors, while the other will be more in depth, the Guardian has learned.

MI5 and British intelligence have a long track record of protecting and enabling terrorists, so any such investigation will be less than futile.

MI5 doesn’t miss “warnings” about terrorist attacks. It simply does not act on them. All the major terror leaders in Britain are monitored. Informers attach themselves to key people. In fact, a number of Islamist movement leaders in Britain are either informers or cooperate with British intelligence.

This has been a fact since at least the early 1980s.

Manchester suicide bomber Salman Abedi is linked to the Libyan Islamic Fighting Group (LIFG). A group of LIFG members lived within close proximity to Abedi in Whalley Range. LIFG is a proscribed terrorist group and listed as such by the UK government, and yet a number of LIFG radicals operated out of Manchester.

Most telling is the accusation MI5 worked with LIFG in a plot to kill Libyan leader Gaddafi (the mission failed).

This fits a distinct pattern. British intelligence allows known and dangerous terrorists to live and organize in the country. It does not act on information gathered by informers on terrorist plots and refuses to allow its collaborators to be prosecuted for crimes committed outside the country. It monitors communication between al-Qaeda and Islamists in Britain and does nothing about it.

The following is a selection of articles from History Commons. It is a timeline showing the deception and mendacity of British intelligence.